I think he does have some sort of interest in Angela. In one of the later chapters, he did tell Rayburn that he likes her (Angela), but on the more later chapters, he thought that he's not as strong as his brother so he doesn't think he can protect her and would be satisfied if he can be allowed to be near her at a safe distance at least. Something about a past memory with his mother that reminds him to not be greedy is also one of the factors why he'd rather not stand in the way of Rayburn & Angela.
To be honest, I think his interest can be interpreted in many ways. For some readers, it could be romantic - yes, but personally for me, it's more of awe & reverence. Both brothers have been chained to their dark pasts for a long time but when Angela came in, they saw her a their "light", and suddenly, their worlds have never been the same as before. Only that given the amount of time Rayburn and Angela spent with each other (and other factors as well), there definitely develops a shift in Rayburn's outlook for Angela. Thus, his revere of her eventually became romantic. Idk, this is just my opinion as another reader (pls don't come at me)
(=・ω・=)
Rereading this and just curious, does the crown prince (the one with blue hair) become the second ml? or does he not have romantic interest in the fl